1. Field of the Invention
The present invention relates to a pole used to extend the elevation of an infusion source that provides fluid during eye surgery.
2. Discussion of the Related Art
Intravenous poles with hangers are used to hang infusion bottles by health care facilities, ambulatory centers, hospitals, nursing homes and physicians in their offices. The ALCON 20000 LEGACY SERIES is used by physicians when performing ophthalmic or cataract surgery employing the MACKOOL SYSTEM.TM. as taught under one or more of the following: U.S. Pat. Nos. 5,026,393; 5,084,009; 5,286,256; 5,354,265, 5,505,693 and 5,569,188. Although the ALCON 20000 LEGACY unit has an intravenous pole incorporated or built into its base, the height of the pole is too short to satisfy the height requirements of the MACKOOL SYSTEM.TM. and/or procedures requiring vacuums of 250 mm or more, if the cassette of the unit is positioned at approximately eye level of the patient. For this reason, a separately standing intravenous pole is used to hang the infusion bottle at the appropriate height.
The ALCON 20000 LEGACY SERIES apparatus includes a base with a slot into which is fitted a cassette containing irrigation and suction lines that convey fluid to or from a phacoemulsification handpiece. The eye level of the patient whose eye is to be operated upon approximately corresponds to the elevation of the center of the cassette when the cassette is inserted into the slot. The cassette also contains valves in the lines to allow the flow rate through the lines to vary as desired by operating appropriate controls on the base via a foot switch.
The ALCON 20000 LEGACY SERIES also includes a telescoping pole of a maximum seventy-eight (78) cm in height and a hanger attached to the pole on which to hang an infusion bottle. The infusion bottle is hung upside down and is connected to the cassette in the base via a supply line. Accordingly, the flow rate and pressure of the liquid in the infusion bottle are limited based on the elevation of the infusion bottle and as regulated by the cassette valves.
The MACKOOL SYSTEM.TM. recommends placing the infusion bottle at a height, relative to the eye level of the patient, of 60-78 cm for purpose of avoiding portal occlusion while carrying out deliberate sculpting of the eye so the vacuum pressure being applied is about 20-40 mm Hg. The bottle height is then raised to 78-110 cm to carry out rapid sculpting (that employs portal occlusion) at about 250 mm Hg vacuum or higher, nucleus impaling at 250-350 mm Hg vacuum during a phaco chop, and nuclear segment removal at 250-350 mm Hg vacuum. Peripheral sculpting such as a one handed technique is carried out with the bottle height at 60-110 cm and the vacuum at 40-150 mm Hg. In all cases which employ the MACKOOL SYSTEM.TM. and all phacoemulsification procedures, the flow rate is 15 cc/mm, although for nuclear segment removal the flow rate may be increased up to 35 cc/mm.
In the absence of an apparatus to elevate the infusion bottle of the present invention, the MACKOOL SYSTEM.TM. is used with the ALCON 20000 LEGACY SERIES by hanging the infusion bottle to a separate IV pole at the appropriate height. Some measurement as to placement of the infusion bottle may be required because the exact location of the infusion bottle corresponding to eye level of the patient is not marked. The separate IV pole may either be at a fixed height or may be adjusted via a telescoping feature such as that described in U.S. Pat. No. 2,957,187 issued on Oct. 25, 1960 to Louis Raia entitled "Telescopic Stand", whose contents are incorporated herein by reference. Aside from this inconvenience in measurement, the need for a separate intravenous pole is in and of itself a burden on the surgeon or support facility in procuring it and finding space to place it.
A need exists to perform eye surgery according to the MACKOOL SYSTEM.TM. but without the inconvenience of relying on a separate IV pole to elevate the infusion bottle to the proper height. An increase of 32 cm in elevation increases intraocular pressure applied to irrigate the eye during eye surgery to satisfy the vacuum pressure demands of the MACKOOL SYSTEM.TM.. A total of 110 cm is measured from the cassette in the base where the irrigation lines emerge (at approximately patient eye level) to the elevation of a stopper in the inverted top of the infusion bottle.